<template>
	<div>
		<router-link 
		tag="div" 
		to="/" 
		class="header-abs"
		v-show="showAbs"
		>
			<div class="iconfont header-abs-back">
				&#xe613;
			</div>
		</router-link>
		<div 
		class="header-fixed"  
		v-show="!showAbs"
		:style="opacityStyle" 
		>景点详情
		<router-link  to="/" class="iconfont header-fixed-back">&#xe613;</router-link>
		</div>
	</div>
</template>

<script>
	export default{
		name:'DetailHeader',
		data(){
			return{
				showAbs:true,
				opacityStyle:{
					opacity:0
				}
			}
		},
		methods:{
			handleScroll(){
				console.log("111")
				const top = document.documentElement.scrollTop
				if(top > 60) {
					let opacity = top / 140
					opacity = opacity > 1 ? 1:opacity
					this.opacityStyle = { opacity }
					this.showAbs = false
					// 这里实现渐隐渐现的效果
				}else{
					this.showAbs = true
				}
			}
		},
		activated () {
			window.addEventListener('scroll', this.handleScroll)
		},
		deactivated () {
			window.removeEventListener('scroll', this.handleScroll)
		}
	}
</script>

<style lang="stylus" scoped>
	@import '~styles/varibles.styl'
	.header-abs
		position:absolute
		left:.2rem
		top:.2rem
		width:.8rem
		height:.8rem
		line-height:.8rem
		border-radius:.4rem
		text-align:center
		background:rgba(0,0,0,.8)
		.header-abs-back
			color:#fff
			font-size:.4rem
	.header-fixed
		z-index:2
		position:fixed
		top:0
		left:0
		right:0
		overflow: hidden
		height:$headerHeight
		line-height:$headerHeight
		text-align:center
		color:#fff
		background:$bgcolor
		font-size:.32rem
		.header-fixed-back
			position:absolute
			top:0
			left:0
			width:.64rem
			text-align:center
			font-size:.4rem
			color:#fff
</style>
